1. Field of the Invention
The present invention relates to an electric cooker, and more particularly, to an electric cooker designed to insulate against heat generated from a heating member.
2. Description of the Related Art
Generally, an electric cooker carries out cooking operations using a heat source produced by converting electricity into heat.
The conventional cooker is typically provided with a casing that includes a cooking plate at a top thereof, to allow cooking containers to be placed on the cooking plate. The electric cooker further includes a heater to serve as a heat source, and a control unit to drive the heater via electric signals, both of which are provided below the cooking plate. To prevent heat generated by the heater from affecting the control unit disposed below the casing, the heater is spaced apart from the control unit or heat insulating material, such as glass fiber, is provided between the heater and the control unit.
According to the conventional electric cooker, where the heater is spaced apart from the control unit by a predetermined distance, the resulting electric cooker product has an increased thickness, thereby, making production of a thin product complex. Furthermore, where a heat insulating material, such as glass fiber, is provided between the heater and the control unit, production of the electric cooker becomes more complicated and costly.
Japanese Patent Laid-open No. Hei6-304074 discusses an electric cooker provided with a heating sheet, on which a conductive resistive element is patterned, in place of the heater. According to this electric cooker, the heating sheet is spaced apart from an object disposed therebelow or a heat insulating member, such as ceramic fibers rather than the glass fiber, is closely attached to a lower surface of the heating sheet. Accordingly, productivity is improved and the product is thinner while production costs are lowered.
Because the heat insulating member of the conventional electric cooker is made of ceramic fibers having a high heat resistance, productivity and production costs of the electric cooker made of the ceramic fibers are superior to those of the electric cooker made of glass fibers. However, the electric cooker made of ceramic fibers has a relatively deteriorated heat insulating property, thus, causing heat efficiency to decrease.
Further, because the heating sheet of the conventional electric cooker includes a heat insulating member attached thereto, the heat insulating member and the heating sheet may burn out in cases where the heat insulating member and the heating sheet have thermal expansion coefficients different from each other.